This invention concerns modular plastic conveyor belts, and specifically a modular belt with flights at selected positions to move conveyed products along, usually on inclines.
Conveyor belts formed of plastic modules are highly versatile in being capable of fabrication in virtually any length or width, and the belts can include various accessories. One type of accessory is known as a flight. Flight modules usually take the place of regular modules in some or all of a module row, so as to provide a pushing device for conveyed products on inclines and to prevent accumulation. Alternatively, flights can be connected to modules. Often used in food industries, these flights can be employed in conveying potato chips, crackers, vegetables, fruit, breads and other food products. Modular flight or added-on conveyor belt flights are shown, for example, in U.S. Pat. Nos. 6,695,135, 6,554,129, 5,469,956, 5,413,211 and 5,165,514. The flights are primarily used for incline applications, although the same flighted belt often goes through both inclined and horizontal sections.
One problem or limitation with flights is that in situations where the belt must be scraped clean of product, the flights interfere with scraping the belt. Food products with oils often tend to stick to the belt even where the belt returns around a roller, so that the belt has to be scraped to remove the conveyed items. Thus, conventional flights often cannot be used in situations where they are needed or would be helpful.
It is an objective of this invention to produce flights dynamically in the travel of a belt, flights that are present on the belt where needed but not in locations where the conveyed product is to be scraped off the belt. Flights with this general function have been provided previously (as in Dutch patent publication No. 1021084, Jan. 20, 2004), but have not been effectively and efficiently held down in areas where the belt is desired to be flat.